1. Technical Field
Capsulated abrasive compositions and polishing pads using the same are disclosed. More specifically, a polishing pad coated with compositions containing a capsulated abrasive that are used for planarizing interlayer insulating films formed on semiconductor substrates by chemical mechanical polishing (hereinafter, abbreviated to ‘CMP’).
2. Description of the Related Art
In general, a CMP process is performed by combining a chemical reaction and a mechanical reaction. The chemical reaction is between the etching solution contained in the slurry and the film to be polished. In the mechanical reaction, a force applied by a polishing pad is transmitted to the abrasive in the slurry, and the abrasive mechanically grinds the chemically reacted film.
In a conventional CMP process, a rotating polishing pad and a wafer are directly contacted under pressure, and the slurry containing the abrasive and the etching solution is provided to the interface between the pad and wafer. That is, the surface of the wafer is planarized by chemical mechanical polishing.
Accordingly, a polishing speed, and a defect and erosion of the polished surface are varied due to the abrasive and the etching solution which are contained in the CMP slurry.
The conventional CMP process using the slurry containing the abrasive requires about 200˜300 mL/min of slurry per wafer, and only about 20˜30% thereof is actually used in the CMP process; the remainder is wasted.
And, when the CMP process using conventional slurry is carried out, it generates waste solution containing the polishing by-product, the abrasive and the etching solution.
For example, when CMP process is applied about 3˜4 times per wafer, about 2˜4 L of CMP slurry is used, and the amount of waste solution generated by CMP process is about 2000˜4000 L per one thousand wafers. As a result, additional costs are required to treat the waste solution.
However it is difficult to reduce the amount of the slurry for the CMP process. Moreover, using reduced amounts of slurry lowers acceptable polishing speed.
As long as conventional overpolishing is applied to the CMP process, there are problems of dishing and erosion due to an irregular distribution of pressure between different materials of the device being processed, the content of the abrasive and the influence of the oxidizing agent containing the metal CMP slurry.